The phytochemical and bioactivity profiles of wild Calluna vulgaris L. flowers

The nutritional composition of Calluna vulgaris flowers as well as the phytochemical profile, antioxidant (DPPH and FRAP assays), antimicrobial and cytotoxic (in human immortalized non-tumorigenic keratinocyte and fibroblasts) activities of aqueous, hydroalcoholic and ethanolic extracts were evaluated. A high content of fiber and carbohydrates (75%) and the prevalence of α-tocopherol as vitamer deserves attention. Linolenic (35%), linoleic (27%) and palmitic (21%) acids were the most abundant fatty acids. Qualitative and quantitative analysis by LC-MS and 1NMR indicated high levels of quercetin, kaempferol and myricetin derivatives as well as procyanidins. The hydro-alcoholic extract displayed the highest antioxidant activity and total phenolics (TPC) and flavonoid contents (TFC). No adverse effects on cells were observed until a concentration of 100 μg/mL and a good antimicrobial activity was reported against S. epidermidis and S. aureus with the hydro-alcoholic extract. The data obtained demonstrated that wild plants like heather, although not being a common nutritional reference, can be used in an alimentary base as a source of bioactive compounds, namely antioxidants.This work received financial support from the European Union (FEDER funds through COMPETE), under the partnership Agreement PT2020, and National Funds (FCT, Foundation for Science and Technology) through project LAQV/UID/QUI/50006/2013–POCI/01/0145/FEDER/007265. Francisca Rodrigues is thankful for her post-doc research grant from the project Operação NORTE-01-0145-FEDER-000011. Diana Pinto is thankful for the research grant from project UID/QUI/50006. M. Antónia Nunes and Filipa B. Pimentel are grateful to the Foundation for Science and Technology (FCT, Portugal) for the PhD fellowships (SFRH/BD/130131/2017 and SFRH/BD/109042/2015, respectively) financed by POPH-QREN and subsidised by the European Science Foundation and Ministério da Ciência, Tecnologia e Ensino Superior. Tânia Gonçalves Albuquerque is grateful for the PhD fellowship (SFRH/BD/99718/2014) funded by FCT, FSE and MEC.